Beams, trusses, joists, and columns are the typical structural members that support the weight or loads of structures, including buildings and bridges. Structural members may be manufactured from a variety of materials, including steel, concrete, and wood, according to the structure design, environment, and cost. Wood furniture such as desks and bookshelves support weight such as computer and office equipment and heavy reference books.
Wood structural members are now typically manufactured from multiple wood segments that are bonded together, such as in glue-laminated members, laminated veneer lumber and I-beams. They can also be manufactured with wood fibers in a polymer matrix such as parallel strand timber or orientated strand board. These manufactured wood structural members have replaced sawn lumber or timbers because the former have higher design limits resulting from better inspection and manufacturing controls. Wood is a desirable material for use in many structural members because of its various characteristics, including strength for a given weight, appearance, cyclic load response, and fire resistance.
In any application, a load subjects a structural member to both compressive and tensile stresses, which correspond to the respective compacting and elongating forces induced by the load on opposite sides of the member. By convention, a neutral plane or axis extends between the portions of the member under compression and tension. The structural member must be capable of bearing the compressive and tensile stresses without excessive strain and particularly without ultimately failing.
Reinforcement of wood structural members in regions subjected to tensile stresses are known. For example, U.S. Pat. No. 5,026,593 of O'Brien describes the use of a thin flat aluminum strip to reinforce a laminated beam. The use of a synthetic tension reinforcement having multiple aramid fiber strands held within a resin matrix adhered to at least one of the wood segments in the tension portion of the structural member is described by the inventor of the present application in "Reinforced Glued-Laminated Wood Beams" presented at the 1988 International Conference on Timber Engineering.
U.S. Pat. Nos. 5,362,545 and 5,456,781 of Tingley describe methods of adhering the reinforcement to wood using conventional non-epoxy adhesives.
Manufacture of the above-mentioned reinforced structural members results in a significant amount of waste of the relatively expensive synthetic reinforcement material. This waste is generally the result of a planing process used to reduce the outside edges of the structural member to produce finished outer side edges. Additionally, planing away the synthetic reinforcement fiber strands causes significant wear on the cutting tools.
Therefore, a need exists for a method of producing structural wood members with synthetic reinforcements without significant waste of the synthetic reinforcement material. Furthermore, a need exists for a method of producing a finished edge on a structural wood member without significant wear of the cutting tools.